How do you handle these situations?
I’ve done a bit of supply work, and if it’s a rare situation, then students will tend to get on with things. But if their regular teacher hasn’t been in a while, then a bad attitude and behaviour problems can develop, that are hard for supply/substitute teachers to manage.
Remind the student that is their responsibility to be prepared for all of their classes on a daily basis, regardless of whether or not their regular teacher will be taking the class. Remind them of their assigned task, and that another regular member of teaching staff will be following up on the work they do.
Sometimes they are used to disruption and for whatever reason, are continuing the disruption. Do not give them an emotional response, just guide them towards spare materials in the classroom, or asking a classmate to share politely. Keep track of behaviour throughout the class, lest this is an attempt to derail or procrastinate.